The answer to the question of whether you can have a roof box and bike racks on the roof of your car at the same time is “yes.” You can basically always put on the roof of your car a roof box and one bike rack, a roof box and two bike racks are possible most of the time (some precautions must be taken though), a roof box and three bike racks are going to be much more challenging due to lack of space and load capacity limits that you are going to be facing.
There are three main things that you have to take into account when installing both accessories:
- First and foremost, roof boxes and roof bike racks are both getting installed on roof bars. A roof bar system has some load capacity, normally it is 160-200 lbs (70-90 kgs). You can still put a roof box and two bikes on the roof without exceeding the load capacity, but you won’t be able to use the full load capacity of the roof box,
- Also, not all roof boxes and roof bike racks are compatible with all roof bars so keep it in mind as well,
- Finally, make sure that there will be enough space on the roof to fit them all.
Can I have a roof box and one bike rack at the same time?
You can do it most of the time. The only thing that can be a problem in this particular case is the load capacity of the roof rack system (you will be attaching the roof box and the bike rack to it).
It will be wise to check the load capacity that your roof racks have, but in my experience, it has never been the case.
In the worst-case scenario, you won’t be able to use the full load capacity of the roof box so that the roof rack system won’t get overloaded.
Lack of space won’t be an issue as well. It is true that some roof boxes take up the whole roof, but in this case, it is pretty much obvious that you can’t install a bike rack.
Can I have a roof box and two bike racks at the same time?
You can do it basically always. However, you must be aware of the load capacity of the roof rack system.
A typical roof rack system can carry 160-200 lbs (70-90 kgs).
A roof bike rack normally weighs 7-20 lbs (approx. 10 lbs for fork mount type and approx. 18 lbs for wheel mount type). Each bike will probably weigh another 15 lbs. So we have:
15 lbs (rack) + 15 lbs bike = 30 lbs x 2 bikes = 60 lbs
+
60 lbs (an empty roof box on average) = 120 lbs
So depending on your roof rack’s load capacity, there are 40-80lbs left that can be carried in the roof box.
So yeah, if you are planning to install a roof box and two bike racks, you have to do some math before. You won’t be able to fully load the roof box, but such construction is completely possible.
Can I have a roof box and three bike racks at the same time?
This is possible but will be quite challenging. Not only because of the load capacity that your roof rack system has but lack of space as well.
A typical roof rack system can carry 160-200 lbs (70-90 kgs).
15 lbs (rack) + 15 lbs bike = 30 lbs x 3 bikes = 90 lbs
+
60 lbs (an empty roof box on average) = 150 lbs
There are 10-50lbs left that can be carried in the roof box. Not much to put it mildly. As a result, you would have to have at the higher end load capacity racks. However, if you need to transport voluminous but rather lightweight cargo, such construction can make practical sense.
Please keep in mind that it might be physically impossible to accommodate a roof box and three bike racks (will highly depend on the roof racks’, roof box’s and bike racks’ particular model).
Can I have a roof box and four bike racks at the same time?
It is impossible because there is simply no enough space to accommodate them all.
Moreover, if there were no space issue, it still would not be possible because of the load capacity of the roof rack system. You would be able to carry an empty roof box, which would not make any sense.
Conclusion
As you can see, you can have both a roof box and at least two bike racks installed. Do not exceed the load capacity of roof bars, because your roof racks can get destroyed damaging your car or other vehicles on the road along the way.